physical education. n. (Education) training and practice in sports, gymnastics, etc, as in schools and colleges. Abbreviation: PE. physâ²ical educaâ²tion. n. instruction in sports, exercise, and hygiene, esp. as part of a school or college program.
3. Stress/injury. Stress on the tissues or any type of injury in the mouth can cause canker sores. Since the sores are actually tiny ulcers, they can be caused by any kind of hard brushing or eating something that can cause bruises or lead to tissue inflammation in the mouth.
Things that cause irritation include: 1  A rough tooth. Maybe it's a broken edge, or a sharp edge where the tooth has worn down. 2  A rough filling or crown. If a filling is crown is broken, leaving rough edges, it can rub on the cheek or tongue. 3  Denture that don't fit well, and move around on the gums, producing a constant small rubbing action.